Electric ignition system for internal-combustion engines.



F. KRATZ. ELECTRIC IGNITION SYSTEM FOR INTERNAL COMBUSTION ENGINES.

- APPLICATION FILED SEPT. 19, 1911.

' 1,063,555. I Patented June 3,1913.

2 sums-sum 1.

MTB ESSES III\I\/YEI\QITDF P. KRATZ.

ELECTRIC IGNITION SYSTEM FOR INTERNAL COMBUSTION ENGINES.

APPLICATION 111,211 $21 1.19, 1911.

Patented June 3, 1913.

2 SHEETS-SHEET 2.

uuumu 1i? WITNESEE bratory armature of the ignition coil is used UNITED STATES PATENT OFFICE.

FRANZ KRATZ, STUTTGART, GERMAIIY, ASSIGINOIt TO THE FIRM OF ROBERT BOSCH, 0F STUTTGART, GERMANY.

ELECTRIC IGNITION SYSTEM FOR INTERNAL-COMBUSTION ENGINES.

Specification of Letters Patent.

Patented June 3, 1913.

Application filed September 19, 1911. Serial No. 650,248.

To all whom it may concern Be. it known that I, FRANZ KRA'rz, a subject of the Emperor of Germany, and residing at Stuttgart, Germany, have invented certain new and useful Improvements in Electric Ignition Systems for Internal-Combustion Engines; and I dohereby declare thefollowing to be a full, clear, .and exact description of the invention, such as will enable others skilled in the art to which it ap 'ierta'ins to make and use the same.

The invention relates to apparatus for starting multiple cylinder combustion engines ofthat kind wherein, after the engine is stopped, it may again be started by ignition it an ignitible gas is present in one of the cylinders.

To that end there is employed an ignition coil, a mechanical interrupter driven by the engine, and a switch for completing the circuit oi the ignition coil when the mechanical interrupter assumes such a position that the ignition coil is otherwise rendered inoperative, these elements being constructed and connected together in the manner and for the purpose hereinafter described.

In one previous arrangement the vibratory armature of the ignition coil is used for the starting ignition, and also for running ignition, the winding and the vibratory armature of the ignition coil being. connect ed in series with the mechanical interrupter. In such case it is only necessary to provide a switch to close the circuit of the ignition coil at will in the event that the engine stops with=the circuit open at the mechanical interrupter.

In another previous arrangement the Vionly for starting, and during running the mechanical interrupter is relied upon to lilfll-Zc and break the circuit of the winding of the ignition coil to produce the ignition sparks. In. the latter case the vibratory armature of the ignition coil and the inter rupter are connected in parallel while the winding of the ignition coil is in series with the interrupter, and it it happens that'the engine stops with the mechanical interrupter closed, there is always a closed current path i through the winding of the ignition coil, and the vibratory armature is conse p1ently drawn a 7 all times toward the magnet and i cannot. operate. This ditliculty is overcome, i

in that case, by providing a switch adapted to close the buzzer circuit of the ignition coil independently of the mechanical interrupter, and further adapted, in the event that the engine stops with the mechanical interrupter closed, to open the circuit of the mechanical interrupter and thereby release the vibratory armature of the ignition coil. This expedient, however, while it attains the desired result, at the same time introduces the difiiculty that the starting switch, if it is held closed, brings about a continuous operation of the vibratory armature, and

as the rotating distributer, which. distributes the sparking current to the several cylinders, establishes a connection with the spark plug of any particular cylinder, the spark due to the action of the vibratory armature will be immediately set up, causing premature ignition and back fire. This could not occur in the old arrangement,in which no provisionwas made for breaking the circuit through the mechanical interrupter, for the reason that the parts are so timed that the mechanical interrupter is closed at the period when the distributor starts to make connection with the spark plug of any particular cylinder, and remains closed until the closure of the circuit at the distributer contact iscomplete and the piston of that particular cylinder has reached the point of proper ignition, whereupon the mechanical interrupter is opened by its cam to cause the spark.

In accordance with'the present invention, the above-mentioned difliculty is avoided by providing such an arrangement that there is av distinction between the mode of operation when the engine has stopped with the mechanical interrupterclosed, and the mode of operation when the engine has stopped with the mechanical interrupter open. In the. event that the engine stops with the mechanical interrupter open, ignition brought about by closing the circuit of the ignition coil through the vibratory armature and the auxiliary switch but. without having the ii'derrupter circuit. open at that time at a second point. The resultis that as soonas the engine starts the mechanical interrupter has the above described effect to render the v bratory ari'nature inoperative j ust before the proper sparking periods, thereby preventing premature ignition and back firing.

In the event that theengme stops with the mechanical interrupter closed, then the arrangement is such that the manipulation of the auxiliary switch first .breaks the inter rupter circuit, causing a single spark, and then immediately closes the interrupter circuit again, before the auxiliary switch has been moved far enough to bring the vibratory armature into circuit. The result is but the interrupter circuit is not opened at a second point at any time when the buzzer is in action and consequently the mechanical interrupter retains its effect to properly control the sparking periods. In this way the engine may be started by the initial spark referred to, or bysetting up a number of sparks in succession by rapid repetition of the movement of the auxiliary switch. As soon as the engine starts the sparking is immediately controlled by the mechanical interrupter, and premature ig- 'nition and back firing are prevented.-

In the accompanying drawings, illustrating the preferred arrangement of my invention, Figure 1 is a wiring diagram, and Fig. 2 shows the auxiliary switch and cooperating contacts in connection with the primary Winding of the ignition coil.

Referring to thedrawings, l is a battery, 2 an ignition coil having a. vibratory armature ,3, one terminal of the primary wind ing 79 being grounded through a switch 10 and the other terminal; being connected to one side of a battery.- The push button 5 is normally heldfopt of contact with the vibratory armature by the spring 12, but is capable of contacting therewith at the cooperating contacts "13 and 14. The push button is permanently grounded as indicated. The mechanical interrupter 6 and the distributer Saredriven by theengine in the we'll/known manner. .The spark plugs 9 in the cylinders of/the'engine are electrically/connected through the distributer to the secondary winding of the ignition coil, and the condenser 7'is bridged across the cooperating contacts, in the usual manner.

The arrangement disclosed herein is dist-inguisl'iedfrom the previously mentioned arrangements by the auxiliary cooperating contacts 11' and 19, carried on the opposite side of a spring lever against which abuts the spring 12 of the push button 5. The stationary contacts 18 and 20 are electrically connected together and to the mechanical interrupter 6 and are disposed opposite the respective cooperating contacts 11 and 19, in such manner that one terminal of the mechanical interrupter 6 is normally connected I to the battery through the cooperating contacts 11 and 18. The arrangement is such that upon pressing the push button 5, to iut the ignition coil into operation to start the engine, the cooperating contacts 1.1 and 18 are first separated and then the cooperating contacts 19 and 20 are closed before the cooperating contacts 13 and Lt. come together at the endv of the movement.

The operation of the system will now be described.

If the engine comes to rest with the mechanical interrupter (3 in an open position, a slight movement of the push button 5 will not effect vibration of the ignition coil armature 3 since the cooperating contacts l3 and 14 are still separated. lhnvcvcr, when the push button is de n'esscd further, the co operating contacts lI-Jand 1+1 are brought together and. the armature 3 starts to vibrate. Practically at the same time, the cooperating contacts 19 and 20 are brought together so that the mechanical interrupter is then connected in series with the primary winding 7) of the ignition coil 2. As a result of the rapid interrupt-ion of the primary circuit 7; due to the vibration ol armature 3, there are generated in the secondary coil 8 a number of ignition currents following each other in rapid succession and of sullicient intensity to produce a plurality of sparks at that spark plug 9 which is selected by the distributor 8. As soon as the engine starts, the push button isu'eleascd and the ignition current is produced in the ignition coil as a result of the cooperating contacts 11 andlS and the mechanical interrupter 6, whereby no premature ignitions and back firin can occur. If, on the other hand, the engine should come to rest with the mechanical interrupter 6 in a closed position, then as soon as the circuit of the mechanical interrupter is opened by depressing the push button 5 to a point where the cooperating contacts 11 and18 are separated, a single spark is generated at the spark plug 9 due to the interruption of the primary circuit p. If suitable ignition occurs then the engine starts,but otherwise another spark is produced when the push button is further depressed to again close the co operating contacts 19 and 20 in the circuit of the mechanical interrupter.- If necessary, this operation may be repeated several times so that the circuit of the mechanical interrupteris alternately made and broken at the cooperatin contacts 11 and 18 and 19 and 20, whereby a succession of single sparks are produced at the spark plug. In this Way, combustible mixtures which have been confined in the cylinders for some time may be ignited. When the engine starts, the push button 5 is released and the ignition system'ope'rates through the mechanical cranking. Also, any other suitable device "for closing and opening the cooperating contacts may be substituted for the push button,

and an ignition coil with a single winding may replace the ignition coil with the primar and secondar' windin s as herein .V a a cooperating contacts and connections therefor arranged to effect continued vibration of the vibratory armature when the mechanical interrupter is in open position, and to efi'ectsingle movements of the vibratory armature when the mechanical interrupter is in a closed position.

2. An electric ignition system for internal combustion engines comprising a mechanical interrupter driven by the engine and capable of coming to rest in either an open or a closed position, an ignition coil for generating ignition currents, a source of electric current, electrical connections for connecting the source to the ignition coil and the me chanical interrupter, and a switch adapted to complete a path in electrical parallel with the mechanical interrupter and. also adapted to actuate a plurality of coactingeontacts arranged in the path of the mechanical interrupter in such manner as, upon operation with the mechanical interrupter at rest to open the connection to the mechanical interrupter, to complete the circuit through theparallelpath, and also to reestablish the connection to the mechanical interrupter.

3. An electric ignition system for internal combustion engines, comprising a mechancal interrupter driven by the engine and capable of coming to rest in either an open or a closed'position, an lgmtion cm] for gencrating ignition currents, a source of electric current, electrical connections for connecting the source to the buzzer and the mechanical interrupter, and a switch adapted to complete a path in electrical parallel with the mechanical interrupter'and also adapted to actuate a plurality of coacting contacts arranged in the path of the mechanical interrupter in such manner as, upon operation with the mechanical interrupter at rest in a closed position, to interrupt the circuit through the mechanical interrupter, and to complete the circuits through theswitch and the interrupter.

4. An electric ignition system for internal combustion engines, comprising a mechanical interrupter driven by the engine and capable of coming to rest in either an open or a closed position, an ignition coil forgenerating ignition currents, a source of electric current, electrical connections for connecting the source to the buzzer and the mechanical interrupter, and a switch adapted to com plete a path in electrical parallel with the mechanical interrupter and also adapted to actuate a plurality of coacting contacts air-L ranged in the path of the mechanical interrupter in such manner as, upon operation with the mechanical interrupter in an open position,' to'open the connection to the me chanical interrupter, to complete the circuit through the parallel path, and also to reestablish the connection to the mechanical interrupter.

5. An electric ignition system for multicylinder internal combustion engines provided with spark plugs, comprising a mechanical interrupter driven by the engine and capable of coming to rest in either an open or a closed position, an ignition coil having a primary and a secondary winding for generating sparks at the spark plugs, a distributer for distributing the currentsinduced in thesecondary winding of the ignition coil to the spark plugs, a source of electric current, electric connections for connect ing the source to the primary winding of the ignition coil and to the mech cal interrupter, and a switch adapted to complete a path in electrical parallel with the mechanical interrupter and also adapted to actuate a plurality of cooperating contacts arranged in the path of the mechanical interrupter in such manner, as upon operation, to first open :the connection to themechanical interrupter and then to complete the circuit through the parallel path and also to reestablish the connection to the mechanical interrupter.

6. In an ignition system for starting internal combustion engines, an ignition coil having a winding and a vibratory armature, amechanical interrupt-er connected in electrical series with the winding of the ignition coil, and a plurality of co-acting contacts for opening the connection to the mechanicalinterrupter, for completing the circuit of the vibratory armature independently of the mechanical interrupter, and for reestablishing the connection to the mechanical interrupter.

7. In an ignition system for starting internal combustion engines, an ignition coil having a winding and a ibratory armature, a mechanicalinterrupter connected in electrical series with the winding of the ignition coil, and a plurality of co-acting contacts for first opening the connection to the mechaniwal. interrupter, and for then completing the circuit of the vibratory armature independently of the mechanical interrupter and reestablishing the connection to the mechanical interrupter.

8. In an ignition system for starting internal combustion engines, an ignition coil having a Winding and a vibratory armature, a mechanical interrupter connected in electrical series with the winding of the ignition coil, a plurality of co-acting' contacts for opening the connection to the mechanical interrupter, and for completing the circuit of the vibratory armature independently of the mechanical interrupter and reestablishing the connection to the mechanical interrupter, and means for permanently closing the path which is indcpemlent ot the mechanical interrupter.

9. In a system o1 electrical ignition for internal combustion engines, thecombination with an ignition coil having a winding and a vibratory armature for starting ignition and a mechanical interrmater properly timed for ignition during periods of running, of auxiliary cirelzit-controlling mechanism and electrical connections therefor arranged to open the circuit of the mechanical interruptcr, to reestablish that circuit, and then to close the circuit of the vibratory armature, substantially as and for the purpose described.

10. A system of electrical ignition for internal combustion engines provided with av mechanical interrupter, and an ignition coil having a winding and a vibratory armature in combination with auxiliary ci1."cuit-'controlling mechanism and electrical connections therefor arranged to open and close the circuit of said ignition coil and the circuit of said mechanical interrupter in such manner that when the circuit of the vibra tory armature is closed by said auxiliary mechanism the circuit. ofthe mechanical interrupter is also closed thereby, substantially as and for the purpose described.

In testimony whereof I affix my signature, in presence of two witnesses.

Atious'r Itiiaeo, DAVID Knuaenn. 

